I intend to write a couple of in-depth articles describing some of the
effects used in this demo. But it will take some time. Meanwhile, the demo note
on Side 1 contains a brief technical introduction.

You can also find information and opinions about Lunatico on pouët and csdb.

Posted Tuesday 1-Nov-2016 00:29

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Two years...and this is the result? Downright amazing! Always look forward to a new LFT demo, however rarely they come out. Can't wait for the technical explanation!

Random question: about when did you write the music for the demo? I'd imagine it would be really hard to stick to writing a single tune over the course of two years. My guess: you wrote the music at the beginning/early-middle period of development and tweaked it as needed to fit the rest of the demo.

Oh, and one other thing: there's a tiny typo in the VSP tool/demo notes where "Lunatica" is written instead of "Lunatico." Not a big deal-just wanted to let you know. =)

As always, thanks for sharing your incredible technical and musical wizardry with us. Hope to see more soon!

Hi,Congratulations, it's a great demo!I have noticed that the 6581 "old SID" detection code works about 50% of the runs, I've tried it on two different "breadbins" (two different board revisions) and on a very early SX-64. I'm curious about how you try detecting the SID type.Running the demo from the "note & vsp tool" almost always worked on all the 2 breadbins (failed only once actually) and on the SX-64 but it never worked on my only C64C (this one with 8580 SID), it just hang the C64C solidly. Loading the demo directly however worked fine and the demo ran until the end. I've always used the same 1541 (but of course on the SX-64) and the same floppy disk.None of these machines ever showed any VSP memory crash on any channel (using your tool).

AnonymousMon 17-Apr-2017 10:14

Still me, replying to myself:

Running the demo from the "note & vsp tool" almost always worked on all the 2 breadbins (failed only once actually) and on the SX-64 but it never worked on my only C64C (this one with 8580 SID), it just hang the C64C solidly.

Interestingly enough, the C64C has a problem. Another X2016 demo doesn't even start. All games I could try work fine for ever. A hardware test program freezes exactly at the same point every time, showing otherwise no errors on the tests. Lunatico runs fine every time when started directly (load"*",8:run) and freezes the C64C when started from the VSP Note (pressing F8 starts to load from disk, then freezes).I've fixed many C64 in my life, but this fault is really strange. Is there any memory location or CPU instruction that's used only when starting Lunatico from the note?

lftLinus ÅkessonThu 20-Apr-2017 10:52

I've fixed many C64 in my life, but this fault is really strange. Is there any memory location or CPU instruction that's used only when starting Lunatico from the note?

Hi! Sorry to hear that your machine is broken, but happy that the crash wasn't caused by the demo.

While there is no special treatment from the point of view of the demo, there are all sorts of things going on while the note is running, so of course the state of the machine would be different. But you're gonna have to patch an emulator if you want to get a complete list of the differences. One thing that comes to mind is that the note makes use of one of the TOD clocks. But many games do that too.

Are you using a cartridge with a fastloader? If so, try disabling it and see if that changes things.

Regarding your other remark about SID detection failing, that's a known problem with the method I'm using. But it should only misdetect the old sid chip (and thus fail to warn). Are you getting any false positives?

AnonymousSat 22-Apr-2017 16:49

lft wrote:

Hi! Sorry to hear that your machine is broken, but happy that the crash wasn't caused by the demo.

Well, I just found the problem (bad CPU) and replaced it.Now every other symptom vanished, here's the list of the strangenesswith the bad CPU:1) Lunatico never starting from the note.2) Concerto by Perfomers (another X2016 demo, as you know) freezingthe machine right after the RUN command3) IC BURN-IN TEST (an old hardware test program) freezing the C64 at a precise point.

With another CPU, all other symptoms vanished but 1.So, I think it's again something related to the demo and the C64C.Hardware wise, the C64C has some differences, as you surely know, but it's really strange that something completely freezes it while running fine on the older hardware.

lft wrote:

Are you using a cartridge with a fastloader? If so, try disabling it and see if that changes things.

No, it's a plain C64C with some chips changed during the years when they died. CIA #2 is one of the substituted chips, so I can try with a different one, just in case.

lft wrote:

Regarding your other remark about SID detection failing, that's a known problem with the method I'm using. But it should only misdetect the old sid chip (and thus fail to warn). Are you getting any false positives?

No, you're perfectly right. It's only misdetecting the old 6581 SID.

AnonymousThu 22-Jun-2017 20:44

Ok final update :)

No, it's a plain C64C with some chips changed during the years when they died. CIA #2 is one of the substituted chips, so I can try with a different one, just in case.

The substituted CIA was the #1 and indeed, using another one in place of the almost-fully-working-one that I had put in place of a failed one, solved the start from the note problem of Lunatico.That CIA worked well in any other game/demo I could try (not many indeed, but quite a few).I had another occasion to watch the demo on real hardware anyway (old 1702 CRT monitor) :)Best regardsIZ8DWF